SERVER-15997 Make sure stepDown command can be interrupted with killop

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• Closed

SERVER-1423 reads often aren't possible while in fsync and lock mode

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• Closed

SERVER-13995 on stepdown/election, SECONDARY should consume all available oplog

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• Closed

SERVER-15877 Give stepdown command some time to let secondaries catch up by default

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• Closed

SERVER-15946 replSetStepDown without force argument will fail if secondaries are behind and there is any write load

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• Closed